r4man2,
Many Nav/Backup systems mount "in" the dash. Some portable one's go "on" the dash.
The Pioneer AVIC (and other brands) are in-dash units that take the place of your factory stereo system. They feature navigation and they have video inputs for cameras. Pretty neat stuff.
Some of the more portable "on" dash nav units are now sporting video inputs to display your backup camera onto so that you don't have to have 2 devices (or screens) in the cab.
Another option, though not for everyone is to use a small PC (or even a laptop) as a navigation unit running one of the many PC based GPS/Nav applications out there. I run a small PC under the driver's seat. It connects to a 7" touchscreen monitor that I mounted on the dash. It mounts right above the radio but does not sit on the top of the dash. I wanted to minimize any visibility issues. The PC's VGA output displays the PC (for Nav, email etc) on the touchscreen and when I hit the input button on the touchscreen, I can cycle through 2 composite video/audio inputs. I have a bumper camera on input 1 and the trailer backup camera on input 2. Works great for me.
If a person wanted to use a laptop to do all of this, I would suggest using an external monitor such as a 7 or 8 inch touchscreen that also has additional video inputs for the cameras. Some people run camera into a PC via a USB video grabber and it works but there can be some delay in the video as it is captured, digitized and processed to the screen.
Like JP, I too have my Pressure Pro display mounted to a visor. I used Velcro to mount it. I grabbed 12 VDC power from the trip computer in the overhead console and routed it above the headliner to the plastic clip that the visor snaps into. I cut a tiny hole in the clip to bring the wire out. I pulled out just enough so I could use the visor fully up or down. If I need to swing it to the driver's side window, I do need to unplug the Pressure Pro display. But I never move the visor over there.
Best of luck,
Jim
